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Comparison of albumin‐(Gd‐DTPA) 30 and Gd‐DTPA‐24‐cascade‐polymer for measurements of normal and abnormal microvascular permeability
Author(s) -
Roberts Heidi C.,
Saeed Maythem,
Roberts Timothy P. L.,
Mühler Andreas,
Shames David M.,
Mann Jeffrey S.,
Stiskal Michael,
Demsar Franci,
Brasch Robert C.
Publication year - 1997
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.1880070213
Subject(s) - vascular permeability , extravasation , albumin , gadolinium , permeability (electromagnetism) , capillary action , leak , chemistry , nuclear medicine , medicine , pathology , materials science , biochemistry , organic chemistry , membrane , environmental engineering , engineering , composite material
The purpose of this study was to compare a new MR macromolecular contrast medium (MMCM), gadolinium‐diethylenetriamine pentaacetic acid (Gd‐DTPA)‐24‐cascade‐polymer, to a well‐studied prototype MMCM, for the potential of distinguishing tissues of varying endothelial permeability. Three tissue models of varying capillary permeability were studied in a total of 46 rats: normal myocardium (normal capillaries), subcutaneously implanted adenocarcinoma (mild capillary leak), and reperfused infarcted myocardium (high capillary leak). T1‐weighted MRI was performed before and dynamically after injection of either albumin‐(Gd‐DTPA) 30 or the cascade polymer (each .02 mmol gadolinium [Gd] per kg). Data analysis based on a two‐compartment kinetic model yielded estimates of fractional blood volume (BV) (percentage) and fractional leak rate (FLR) (1 per hour). Permeability to the cascade polymer as reflected in FLR was considerable in normal myocardium (8.24 per hour), of similar value in tumors (8.55 per hour), but significantly greater in infarcted myocardium (39.17 per hour, P < .01) versus normal myocardium. The larger albumin‐(Gd‐DTPA) 30 demonstrated minimal extravasation in normal myocardium (FLR .33 per hour); FLR in tumors was 100% higher (.66 per hour, P < .002) and FLR in reperfused capillaries was significantly greater (7.94 per hour, P < .001). Based on capillary permeability measurements, the cascade polymer may have limited utility for detection of mildly increased microvascular permeabilities. For severe tissue injury, the cascade polymer can resolve abnormal microvascular integrity.